Electric fuse.



PATENTED DEC E. GEISENHNEE.

ELECTRIC FUSE.

APPLIOATION FILED MAY 31,'1901.

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WlJmesse-s Henry Geisenhnet PATBNTBD DEG. 22, 1903 H. GEISENHNER.

ELECTRIC FUSE.

APPLIGATION FILED MAY 31. 1901.

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UNITED STATES Patented December 22, 1903.

PATENT OFFICE.

HENRY GEISENHNER, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ELECTRlC FUSE.

SPECIFICATION forming part of Letters Patent No. 747,69*?, dated December 22, 1903.

Application filed May 3l, 1901.

To all whom, it may concern:

Be it known that I, HENRY GEISENHNEE, a citizen of the United States, residing at Schenectady, county of Schenectady, State of 5 New York, haveinvented certain new and useful Improvements in Electric Fuses, of Which the following is a specication.

This invention relates to thermal cut-outs for electric circuits, the object being to pro- Io vide a fuse of small compass Which will more effectively open a circuit, and especially one of considerable voltage, than fuses as ordinarily constructed.

In carrying out the invention I provide a x5 fuse of the cartridge type in which the fuseterminals are mounted on the outside of the cartridge to permit connection with conducting-clips in the fuse-box and in which the fuse-strip is passed a plurality or times across 2o a discharge-opening in the cartridge, the opening through Which it is threaded being of such ay character that one part of the strip is of smaller heat-radiating capacity than the others, by which it is forced to give way first z5 When the limiting-current is reached, thereby directing the hot gases across the other parts of the fuse and breaking the circuit at a number of places practically sim ultaneously, 'thus effectively disrupting the arcs. The ends of 3o the fuse-strip are soldered or otherwise secured in good conductive relation to the terminals at the ends of the cartridge, and the openings, except the d-ischarge vent, are sealed by a covering of asbestos or similar fireproof material. A cartridge of this type is inserted in a fuse-box with vents or discharge-openings in such relation to the Walls of the inclosing chamber that the axne and volatilized products are forced to traverse the cool Walls of the box before discharging into the atmosphere. The fuse-box is provided with a removable cover, having vents between the box-terminals and ribs between the ends of the cartridge-chambers and the terminals, which latter form a barrier against the transit of the gaseous products to the box-terminals, thereby protecting the latter. The box is provided With clips in conductive relation to the terminals, into which the cartridge may be slipped, bringing the fuse-terminals into conductive engagement with the clips.

Serial No. 62.606. (No model.)

My invention comprises a fuse-cartridge having an axial vent and lateral openings through which the fuse-strip is threaded and means on the outside of the cartridge for effecting connection with circuit-terminals. It comprises also, in connection With a cartridge of the general character referred to, a fusebox so related to the cartridge that the volatilized products are forced to discharge across 6o a cool Wall in order to rob them of their heat.

It comprises various other features the novelty of which Will be hereinafter described, and definitely indicated in the claimsl appended to this specification.

In the accompanying draWings,Which illustrate several forms of my invention, Figure l is a plan view of a fuse-box and fuse-cartridge embodying my improvements, the two being assembled in operative relation. Fig. 7o 2 is a cross-sectional view on the plane indicated by the line X X of Fig. l, the terminals and cartridge being shown in elevation. Fig.

3 is a sectional View of the fuse-cartridge. Fig. 4 is a cross-sectional view on the line 75 Y Y of Fig. l. Fig. 5 is a side elevation of a modified form of fuse-cartridge. Fig. 6 is a longitudinal sectional view of a fuse-box and cartridge of modified construction for use With currents of high potential. Fig. 7 is an end view of a cartridge for this type of construction.

Referring iirst to the types shown in Figs. l to 5, l represents a fuse-cartridge made of insulating and preferablyfireproof material, such as porcelain, bored or cored out axially and provided with a plurality'ot' transverse holes 2 2 2b, crossing the axial bore. One of the openings, as 2, is larger than the others, Whichlatter are preferably of a size to snugly admit the fuse-strip of a carrying capacity for the current for which the cartridge is designed. The fuse-strip is threaded through the openings in the manner indicatedin Fig. 3 and the ends soldered to brass rings 3 3a, 95 mounted near the ends of the cartridge. The ends of the cartridge are provided with V- shaped notches, as indicated, so that when placed in the fuse-box these notches will line up With projections J.- Ala from the Walls of the fuse-box, the side Walls of these projections curving, as indicated in Fig. l, toward the IOO sides of a recess or chamber formed in the body of the box. The object of this construction is to cause the volatilized products discharged from the ends of the cartridge when the fuse blows to traverse the cool walls of the box before reaching the atmosphere. The box may be formed of porcelain or other refractory insulating material and is provided with lateral openings or vents 5 5 to the atmosphere. The box shown in the drawings is adapted to accommodate two fuse cartridges, being of the double-pole type, where of the single-pole type but a single recess is formed. Communicating with the cartridgechamber in the fuse-box are metal terminals 6 7 6 7, leading into the cartridge-chamber through channels cut or molded in the boxwalls. Binding-screws for the circuit-terminals are connected with the box-terminals. The box-terminals connect with elastic phosphor-bronze clips, as 8 8, into which the cartridge may be forced to form a good conductive connection with the circuit. The cover of the box is provided with ribs 9 9a, entering corresponding recesses in the top of the box and preventing the gases discharged from the fuse from being discharged over the boxterminals, which would render possible arcing across the terminals. The cover and box are bound into close contact by a bolt l0, a metal plate ll equalizing the pressure of the clamp-nut l2. l/Vhen a fuse of this construction blows, the portion 2, which is of poorer radiating` capacity by reason of its freedom from contact with solid walls, heats up most rapidly and gives way before the other parts of the fuse-strip, when the arc drawn creates volatile products, which effect a hot blast through the discharge-opening and passing across the other portions 2 2 of the fuse-strip cut it and drive sections of it swiftly outward, thereby7 rupturing the arc and opening the circuit at a plurality of points.

With ordinary overloads the amount of fuse volatilized when it blows is comparatively small, and the circuit is opened by small sections of the fuse-strip being driven out from the sections 2 2b of the fuse-strip, the gases being robbed of their heat by transit across the faces of the walls of the inclosing chamber in the fuse-box. On heavy overloads more of the fuse is consumed; but even on short circuits the circuit is effectively opened. The cartridge-chamber in the box contains a wall 13, against which the body of the cartridge rests and which acts as a reinforce for the asbestos covering 13b and prevents rupture of this envelop. Where the square type of cartridge is employed this reinforce-wall is provided with a plain top, as indicated at 13, to provide a seat for the bottom of the cartridge. The square or prismatic type of cartridge is shown in Fig. 5. On blowing the fuse products are driven from the ends of the cartridge impinging against the edge of the ribs e 4, split, and are diverted along the two sides of the chamber,

thus being spread over a large area of cooling-surface, and are finally driven out from the vents 5 5a.

In the type of fuse-box shown in Figs. o and 7 I give the cartridge a shape to forni ridges li 14 14h 14C, coperating with corresponding depressions of the walls of the box and its cover, by which any dilfusion or scattering of volatilized products from end to end of the fuse is prevented, and therefore any chance of the arc hanging is precluded. This type is particularly suitable for currents of Very high tension. Aside from the particulars noted the box and cartridge have the same features of construction as those already described. The asbestos may be simply short strips covering the grooves in the cartridge along which it extends at the points l5 l5 15b 15C.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent of the United States, is-

l. A fuse comprising an axially-perforated cartridge carrying fuse-terminals, and a fusestrip connected to said terminals crossing the perforation a plurality of times.

2. A fuse comprising,r a perforated cartridge having a fuse-strip connected to terminals mounted on the cartridge, and crossing the perforation a plurality of times, one of said crossings being of smaller` heat-dissipating capacity than the others.

3. A fuse-cartridge carrying fuse-terminals, afuse mounted thereon connected to the terminals, a vent crossing the fuse at a plurality of points, and means for decreasing the heat-dissipating capacity at one of said points.

4. A fuse-cartridge provided with an axial discharge-opening carrying a fuse crossing said opening a plurality of times, one crossing-point adapted to give way first under increase of current.

5. A fuse-cartridge provided with a discharge-opening, a fuse-strip crossing said opening and threading the cartridge-walls and extending along the outside of the cartridge, and a heat-refractory packing for the outside parts.

G. A fuse-cartridge provided with an axial discharge-vent and lateral openings crossing the same, fuse-terminals, a fuse connected to the terminals and traversing the lateralopenings, and an asbestos cover for said lateral openings.

7. Afuse comprisinga fuse-holderprovided with a discharge-vent, a fuse mounted there on, a fuse-boxinclosing the holder, and means for spreading the gaseous fuse products over the walls of the box before reaching the vent.

S. Afusecomprisingafuse-holderprovided with a discharge-vent, a fuse mounted thereon crossing said vent a plurality of times, a fuse-box inclosing the holder, and means for spreading the gaseous fuse products over the walls of the box.

9. A fuse comprising a fuse-holder having an axial vent, a fuse-strip crossing said vent,

IOO

IIO

ISO

means for causing a heated blast across the strip when it blows, arefractoryinclosing box containing circuit-terminals, a removable cover having a gas-tight seal in the line of the terminals and a vent to the atmosphere between the terminals.

10. A fuse comprisinga fuse-holder having an axial vent,and a fuse-strip connecting` with fuse-terminals on the outside of the holder, said strip crossing the vent, a fuse-box having a vent to atmosphere containing the holder and gas-tight seats for the holder in the walls of the box.

ll. A cartridge-fuse having an axial discharge-vent and a fuse-strip crossing the same, fuse-terminals on the cartridge secured HENRY GEISENHNER.

Witnesses:

BENJAMIN B. HULL, MARGARET E. WOOLLEY. 

